diff --git a/.hgtags b/.hgtags
index f53a0c4dd198..496e61862d1c 100644
--- a/.hgtags
+++ b/.hgtags
@@ -154,3 +154,4 @@ ccfd7b716a91241ddbc084cb7116ec561e56d5d1 FIREFOX_BETA_61_BASE
 ad179a6fc14cbd41d10a018ac4a3822db119de3b FIREFOX_BETA_64_BASE
 c44fbdd5173548c9035256dda8fd3512f67118a8 FIREFOX_NIGHTLY_64_END
 58a0412e15574f063cd380517a0369bfb48b22e0 PRE_TREEWIDE_CLANG_FORMAT
+9ad82455dcee2bc1d438e46016b8db00e88758a8 FIREFOX_BETA_65_BASE